【请教】关于偶联反应
有哪位达人给通俗的介绍一下偶联反应呢?谢谢了
谢谢楼下的几位了,不过呢 还是有点迷糊,我的理解是两个物质(分子)反应结合成一个物质(分子),反应后有新键生成,比如C-C键生成的反应就叫偶联反应,不知道对不对?
[ Last edited by 红月亮6752 on 2009-11-24 at 08:45 ]
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今日热帖
有哪位达人给通俗的介绍一下偶联反应呢?谢谢了
谢谢楼下的几位了,不过呢 还是有点迷糊,我的理解是两个物质(分子)反应结合成一个物质(分子),反应后有新键生成,比如C-C键生成的反应就叫偶联反应,不知道对不对?
[ Last edited by 红月亮6752 on 2009-11-24 at 08:45 ]
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比如说亲核取代反应
四大偶联反应,自己找去.....
给你介绍本书,黄培强《有机人名反应、试剂与规则》里面介绍了多种偶联反应的机理,试剂!可以参考!
Suzuki Coupling
The palladium-catalysed cross-coupling reaction between organoboronic acids and, for example, aryl halides (known as the Suzuki or Suzuki-Miyaura coupling) is a powerful synthetic tool. It represents one of the most valuable methods for carbon-carbon bond formation, not least because of its tolerance of a broad range of functional groups and its non-toxic by-products. The boronic acid is also thermally stable and inert to air and water which allows easy handling without special precautions.
Chan-Lam Coupling
A recent coupling method discovered and developed at DuPont/BMS involves the formation of a carbon-heteroatom bond by the copper acetate promoted oxidative coupling of a boronic acid (stannane, siloxane or iodonium) with an amine, alcohol, or thiol. The advantages of Chan-Lam coupling over Buchwald-Hartwig Pd-catalyzed N/O-arylation reaction are: room temperature and ambient air. Chan-Lam coupling is an extremely versatile and powerful method of synthesis, complementary to Suzuki-Miyaura's C-C bond cross-coupling.
Negishi Coupling
Possibly the earliest reported heteroaryl, aryl/alkenyl or alkynyl cross coupling reaction is the Negishi Coupling reaction. This versatile reaction is catalyzed by both palladium and nickel species. The Negishi coupling is widely versatile for the synthesis of several different types of materials.
Liebeskind-Srogl Coupling
An extremely useful coupling reaction has recently been developed. Known as Liebeskind-Srogl coupling, this reaction involves the coupling of a boronic acid with a thiol ester to form ketones (J. Am. Chem. Soc. 2000, 122,11260-11261). This reaction is also mechanistically interesting in that the reaction does not use palladium, but uses stoichiometric copper(I) thiophenecarboxylate (CuTC) as a mediator. The reaction is extremely general and even works with base-sensitive functional groups.
Kumada Coupling
Kumada coupling is a well-established method for forming carbon-carbon bonds with a Grignard reagent and a aryl, vinyl, or alkyl halide. The Kumada reaction is less general simply because it is not compatible with any functional groups that react with Grignards. However, the reaction has the advantage that nickel catalysts can often be used. Despite it's limitations, the Kumada reaction is a very powerful and inexpensive method of forming simple biaryls.
Hiyama Coupling
Hiyama coupling is the coupling of organosilanes and organohalides. This method is similar to the Suzuki reaction. An activating agent such as fluoride is often required. This reaction has been expanded by the DeShong group to work with siloxanes.
Carbonylative Coupling
When most cross coupling reactions are performed under a CO atmosphere, the reaction produces a ketone by incorporation of CO. Carbonylative coupling is general nomenclature referring to this type of reaction.
Stille Coupling
Stille coupling is the palladium-catalyzed reaction between an organotin compound and an organohalide. This reaction has the advantage of being slightly more general than the Suzuki reaction, since it does not require base. However, a major drawback is the toxic tin by-products.
Chan-Lam Coupling
A recent coupling method discovered and developed at DuPont/BMS involves the formation of a carbon-heteroatom bond by the copper acetate promoted oxidative coupling of a boronic acid (stannane, siloxane or iodonium) with an amine, alcohol, or thiol. The advantages of Chan-Lam coupling over Buchwald-Hartwig Pd-catalyzed N/O-arylation reaction are: room temperature and ambient air. Chan-Lam coupling is an extremely versatile and powerful method of synthesis, complementary to Suzuki-Miyaura's C-C bond cross-coupling.
[ Last edited by mvpworm on 2009-11-24 at 07:58 ],
不知道就百度啊
偶联反应 (Coupling Reaction)
偶联反应(英文:Coupling reaction),也作偶连反应、耦联反应、氧化偶联,是由两个有机化学单位(moiety)进行某种化学反应而得到一个有机分子的过程.这里的化学反应包括格氏试剂与亲电体的反应(Grinard),锂试剂与亲电体的反应,芳环上的亲电和亲核反应(Diazo, Addition-Elimination),还有钠存在下的Wutz反应,由于偶联反应 (Coupling Reaction)含义太宽,一般前面应该加定语.而且这是一个比较非专业化的名词. 狭义的偶联反应是涉及有机金属催化剂的碳-碳键生成反应,根据类型的不同,又可分为交叉偶联和自身偶联反应。进行偶联反应时,介质的酸碱性是很重要的。一般重氮盐与酚类的偶联反应,是在弱碱性介质中进行的。在此条件下,酚形成苯氧负离子,使芳环电子云密度增加,有利于偶联反应的进行。重氮盐与芳胺的偶联反应,是在中性或弱酸性介质中进行的。在此条件下,芳胺以游离胺形式存在,使芳环电子云密度增加,有利于偶联反应进行。如果溶液酸性过强,胺变成了铵盐,使芳环电子云密度降低,不利于偶联反应,如果从重氮盐的性质来看,强碱性介质会使重氮盐转变成不能进行偶联反应的其它化合物。偶氮化合物是一类有颜色的化合物,有些可直接作染料或指示剂。在有机分析中,常利用偶联反应产生的颜色来鉴定具有苯酚或芳胺结构的药物。
常见的偶联反应包括:
反应名称--年代--反应物A--反应物B --类型--催化剂--注
Wurtz反应 1855 R-X sp³ 自身偶联 Na
Glaser偶联反应 1869 R-X sp 自身偶联 Cu
Ullmann反应 1901 R-X sp² 自身偶联 Cu
Gomberg-Bachmann反应 1924 R-N2X sp² 自身偶联 以碱作介质
Cadiot-Chodkiewicz偶联反应 1957 炔烃 sp R-X sp 交叉偶联 Cu 以碱作介质
Castro-Stephens偶联反应 1963 R-Cu sp R-X sp² 交叉偶联
Kumada偶联反应 1972 R-MgBr sp²、sp³ R-X sp² 交叉偶联 Pd或Ni
Heck反应 1972 烯烃 sp² R-X sp² 交叉偶联 Pd 以碱作介质
Sonogashira偶联反应 1973 炔烃 sp R-X sp³ sp² 交叉偶联 Pd、Cu 以碱作介质
Negishi偶联反应 1977 R-Zn-X sp² R-X sp³ sp² 交叉偶联 Pd或Ni
Stille偶联反应 1977 R-SnR3 sp² R-X sp³ sp² 交叉偶联 Pd
Suzuki反应 1979 R-B(OR)2 sp² R-X sp³ sp² 交叉偶联 Pd 以碱作介质
Hiyama偶联反应 1988 R-SiR3 sp² R-X sp³ sp² 交叉偶联 Pd 以碱作介质
Buchwald-Hartwig反应 1994 R2N-R SnR3 sp R-X sp² 交叉偶联 Pd N-C偶联
Fukuyama偶联反应 1998 RCO(SEt) sp2 R-Zn-I sp3 交叉偶联 Pd